Hyddogen generating apparatus

ABSTRACT

In a hydrogen generating apparatus, in a reactor in which a catalyst is installed, the catalyst and borohydride fuel are reacted, hydrogen generates. The hydrogen generating apparatus comprises a rotating disk to which the catalyst is fixed, a motor for rotating the rotating disk, and a fuel injecting means for blowing out the borohydride fuel against the catalyst. A half-solid shape reactive compound generated from the borohydride is prevented from adhering to the catalyst.

BACKGROUND OF THE INVENTION

The present invention relates to a hydrogen generating apparatus, in particularly relates to a hydrogen generating apparatus in which hydrogen is generated by reacting a borohydride fuel with a catalyst.

Recently, as a hydrogen storing material for storing hydrogen, which becomes a fuel of a fuel battery, it has known the borohydride fuel, which is generated by dissolving a metallic complex compound of NaBH₄ and KB H₄, etc., is dissolved in an alkali aqueous solution.

The borohydride fuel is an extremely stable hydrogen storing and supplying material and has a characteristic in which a large quantity of hydrogen is generated under a normal temperature and a normal pressure using a suitable catalyst.

For example, under a following reaction formula, when it is reacted with 100%, NaBH₄ has an ability in which about 1 liter hydrogen gas is generated from 1 cc of a fuel of 40 wt % and this fuel becomes a good fuel for storing hydrogen.

As a technique for generating hydrogen for the borohydride fuel, as a prior art, there is a hydrogen generating apparatus, for example, in which the borohydride fuel is poured into a reactor (a reaction vessel, a processing vessel) in which the catalyst is provided in an interior portion thereof and then hydrogen is taken out from the borohydride fuel. Such a hydrogen generating apparatus has known in Japanese patent laid-open publication No. 2002-80202.

The reaction formula of NaBH₄ as the borohydride fuel is as following.

(Reaction Formula) NaBH₄+2H₂O+M+(NaOH)→NaBO₂+4H₂+M+(NaOH)

wherein M is a catalyst of a noble metals group, such as platinum, palladium, ruthenium, and a catalyst of magnesium fluoride/nickel hydrogenation, which is made under a low cost and has a high performance hydrogen generating speed.

As stated in above, one molecular of NaBH₄ and two molecular of water (H₂O) for constituting the aqueous solution are catalytically reacted and then hydrogen gas is generated.

Further, at the same time of the hydrogen gas generation, as shown in a right side of the above reaction formula, NaBO₂ is generated as a reactive compound. After a recovery of NaBO₂ as a spent fuel, NaBO₂ is regenerative processed to NaBH₄ and it can be used again as the fuel.

However, in the conventional hydrogen generating apparatus, for example, when NaBO₂ is generated at the same time of the generation of hydrogen from NaBH₄ as the borohydride fuel, there is a problem in which NaBO₂ adheres to the catalyst in the reactor and the reaction after that is made to slow and there is in a danger that hydrogen is not taken out safely with age.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a respective view showing a first embodiment of a hydrogen generating apparatus according to the present invention;

FIG. 2 is a graph showing a relationship between a radial direction position of a rotating disk and a lateral acceleration received by a fuel on the rotating disk and a reactive compound;

FIG. 3 is a cross-sectional view showing a modified embodiment of a hydrogen generating apparatus according to the present invention;

FIG. 4 is a graph showing a relationship between an opening time of a valve of an injector and a fuel injecting amount;

FIG. 5 is a cross-sectional view showing a second embodiment of a hydrogen generating apparatus according to the present invention;

FIG. 6 is a time chart showing one example of a control for supplying intermittingly a fuel against a catalyst;

FIG. 7 is a perspective view showing a third embodiment of a hydrogen generating apparatus according to the present invention;

FIG. 8 is a time chart showing operation states of respective valves; and.

FIG. 9 is a cross-sectional view showing a fourth embodiment of a hydrogen generating apparatus according to the present invention and showing fore and aft of usage of a fuel tank for connecting the hydrogen generating apparatus.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a hydrogen generating apparatus wherein a harmful influence concerning to a reactive compound generated from a borohydride fuel is prevented from adhering to a catalyst and a stable operation is performed at a long time period.

In a hydrogen generating apparatus according to the present invention, in which in a rector for accommodating a catalyst, the catalyst and a borohydride fuel are reacted and hydrogen is generated, the hydrogen generating apparatus comprises a rotating body in which the catalyst is fixed, a rotation driving means for rotating the rotating body, and a fuel injecting means for blowing the borohydride fuel against the catalyst.

According to the hydrogen generating apparatus according to the present invention, the reactive compound, which is generated in the reactor together with hydrogen, is centrifugally separated in accordance with the rotating body.

DESCRIPTION OF THE INVENTION First Embodiment

Next, a first embodiment of a hydrogen generating apparatus according to the present invention will be explained referring to figures.

FIG. 1 is a perspective view showing a first embodiment of a hydrogen generating apparatus according to the present invention. FIG. 2 is a graph showing a relationship between a radial direction position of a rotating disk and a lateral acceleration, which received by a fuel and a reactive compound on the rotating disk.

As shown in FIG. 1, a hydrogen generating apparatus 1 in which by reacting a solid type catalyst M and a liquid type borohydride fuel (hereinafter, it is said merely as “fuel”), hydrogen is generated.

The hydrogen generating apparatus 1 comprises mainly a reactor 2 being a hollow case for accommodating the catalyst M, a rotating disk (a rotating body) 3 for fixing the catalyst M, a motor (a rotation driving means) 4 for rotating the rotating disk 3, and a fuel injecting means 5 for blowing the fuel against the catalyst M.

The reactor 2 constitutes mainly a rotating disk receiving portion 21 and a substantial cylindrical-like shape projecting portion 22, which is formed projected toward an outer portion from a center portion of an upper wall 21 a of the rotating disk receiving portion 21. The rotating disk receiving portion 21 and the projecting portion are formed as one body to communicate each other.

A groove portion 21 c is formed on a lower wall 21 b of the rotating disk receiving portion 21 to expand at a lower portion at an outer peripheral portion thereof. An engaging hole 21 d for supporting rotatably a rotating shaft 41 of the motor 4 and for sealing the generated hydrogen is formed on a center of the groove portion 21 c.

A deriving tube 21 f is formed integrally at an appropriated place of a bottom wall 21 e of the groove portion 21 c. The deriving tube 21 f introduces the reactive compound RC such as NaBO₂ generated by a reaction between the catalyst M and the spent fuel such as water being a fuel solvent etc. after the reaction to a spent fuel tank 57 of a fourth embodiment according to the present invention stated in latter. Further, the projecting portion 22 is an introducing tube in which hydrogen gas generated in the reactor 2 is introduced to a fuel battery (not shown in figure).

The rotating disk 3 has a substantially circular plate-like shape and at a center thereof the rotating shaft 41 of the motor 4 penetrates through and is fixed to the rotating disk 3. The catalyst M is fixed with a substantial ring shape to an upper face 32 of the rotating disk 3.

The motor 4 is constituted mainly with the rotating shaft 41, which extends over to a vicinity of a tip end of the projecting portion 22 from a vicinity of the lower wall 21 b of the reactor 2, and a main body portion 42, which rotates the rotating shaft 41. The rotating shaft 41 is supported rotatably by the engaging hole 21 d formed on the lower wall 21 of the reactor 2 and a bearing portion 23 which is fixed to an inner portion of the projecting portion 22. The bearing portion 23 has a filter portion to enable to pass through only the gaseous body.

The fuel injecting means 5 comprises mainly a fuel tank 51 of the fourth embodiment according to the present invention stated in latter, a pressurizing pump 52, an injector 53, piping 54, 55, and a valve 56. The fuel tank 51 is a tank for storing borohydride fuel and is connected to the pressurizing pump 52 through the piping 54. The valve 56 is installed at an appropriated place of the piping 54 and when the valve 51 is opened the fuel is discharged from the fuel tank 51 and when the valve 51 is closed a flow of the fuel discharged from the fuel tank 51 is opening and closing controlled.

The pressurizing pump 52 supplies the fuel to the injector 53 by pressurizing the fuel sent from the fuel tank 51 and is connected to the two injectors 53, 53 through the forked branched shape piping 55. The injector 53 blows the fuel discharged from the pressurizing pump 52 toward the catalyst M. This injector 53 is fixed at an appropriated place of the upper wall 21 a of the rotating disk receiving portion 21 to blow the fuel to a place, such a place is remote with a predetermined distance toward a radial direction from the center of the rotating disk 3.

The catalytic reaction of the rotating disk 3 operates with an operating distance between the fuel injecting point and an outer periphery of the rotating disk 3 and proceeds together with the fuel flow, which is generated according to a centrifugal force in this operating distance. The fuel flow concerns to the centrifugal force, which is determined according to a radial dimension and a rotating number of the rotating disk 3.

In response to a hydrogen gas generating speed of the catalyst to be applied, the fuel flow is set at an optimum value to finish the reaction having approximately 100% in the above operating distance.

For example, it is 1 G at the injecting point and is 3 G at the outer periphery, and when a distance toward the radial direction form the rotating shaft is R, according to a formula an acceleration G=Rε² (ε: angular acceleration), the above predetermined distance is set to have about one third of a radial of the rotating disk 3.

As shown in FIG. 2, at the fuel injecting point, a small lateral acceleration having nearly 9.8 m/s (1 G) is acted on the fuel and the fuel reacts with the catalyst M under a suitable velocity and flows toward an outer portion.

In this time, in addition to the hydrogen gas generation, the reactive compound RC and water such as the fuel solvent, etc. are flown, however the reactive compound RC and water etc. are pushed out to the outer portion according to the centrifugal force.

When the reactive compound RC and water etc. reach to a vicinity of a peripheral edge of the rotating disk 3, the radial dimension and the angular acceleration of the rotating disk 3 are set to add a high lateral acceleration velocity having more than 29.4 m/s² (3 G).

As a result, the reactive compound RC and water etc. are separated surely from the catalyst M and flied out toward the outer portion. The filed-out reactive compound RC etc. are fallen into the groove portion 21 c and flown into the recovering use tank from the deriving pipe 21 f.

As stated in above, in the first embodiment according to the present invention, following effects will be obtained.

The fuel can flow on the contacting area under the small lateral acceleration at the fuel injecting point and under the comparative low velocity and the catalytic reaction time can secure. The fuel can spread to a disk shape catalyst face according to the centrifugal force and then the contacting area between the catalyst M and the fuel is formed largely, accordingly the reaction is promoted.

Further, the reactive compound RC generated together with the hydrogen gas is centrifugal separated according to the above lateral acceleration, which becomes high in proportion to a surrounding of the rotating disk 3, and then the reactive compound RC is prevented surely from adhering to the catalyst M.

The present invention will not to limit to the first embodiment according to the present invention but will be carried out on the various embodiments. In this first embodiment according to the present invention, the two injectors 53 are provided, however the present invention will not limit to this structure. For example, according to the supply amount of hydrogen, a number of injector 53 is increased or decreased.

A modified example of the first embodiment according to the present invention will be explained referring to FIG. 3. The constituting elements similarly to the first embodiment according to the present invention will be indicated with the same reference numerals.

When much quantity hydrogen generates, as shown in a cross-section view shown in FIG. 3 the rotating disk 3 is constituted with plural stages. The fuel flows into the respective rotating disks 3 a, 3 b, 3 c according to the centrifugal force and the flow force generates.

Flow passages are constituted to flow the fuel in series on the rotating disk 3 as shown in an arrow mark 33. Accordingly, the distance for performing the catalytic reaction is enlarged and then against much quantity hydrogen a self-contained hydrogen can be generated with 100%.

Second Embodiment

Hereafter, a second embodiment of a hydrogen generating apparatus according to the present invention will be explained.

Since this second embodiment is performed according to the alternation of the first embodiment of the hydrogen generating apparatus 1, the constituting elements similarly to those of the first embodiment are expressed with same reference numerals shown in the first embodiment. FIG. 5 is a cross-sectional view showing a second embodiment of a hydrogen generating apparatus according to the present invention.

As shown in FIG. 5, a hydrogen generating apparatus 1′ comprises a reactor 2′, a cone body (a rotating body) 6, and a catalyst M′, they have different structures shown in the first embodiment. The reactor 2′ has a cone cylindrical portion 25, which is formed as one body between the rotating disk receiving portion 21 and the projecting portion 22.

The cone cylindrical portion 25 is formed with a cylindrical-like shape one, in which a diameter thereof becomes larger in companying with a direction for directing a lower portion. The two injectors 53, 53 are arranged to direct toward an interior portion at an upper end portion of the cone cylindrical portion 25.

The cone body 6 is formed with a column-like shape (a shape in which a top portion of the cone body is cut off), in which the diameter thereof becomes larger in companying with the direction for directing the lower portion. This cone body 6 is joined to the rotating shaft 41 of the motor 4 and a lower face thereof is joined to the rotating disk 3. Further, the catalyst M′ is fixed to the cone body 6 to cover an outer peripheral face of the cone body 6. An operation of this second embodiment will operate similarly to that of FIG. 1.

As stated in above, in this second embodiment according to the present invention, following effects can be obtained. Since the catalyst M′ is installed on a whole outer peripheral face of the substantially cone-like shape cone body 6, a surface area of the catalyst M′ is formed extremely large and accordingly the hydrogen generating apparatus 1′ is formed with a compact size.

As stated in above, the present invention will not to limit to the first embodiment and the second embodiment according to the present invention but will carry out on the various embodiments.

Further, a fuel supplying control in the first embodiment and in the second embodiment according to the present invention will be explained.

As the means for controlling the amount of the fuel, for example, to supply intermittingly the fuel from the injector 53 shown in FIG. 1, against the catalyst M with a predetermined time interval, a controlling means for controlling an opening and closing of an electromagnetic valve in the injector 53 is provided.

As a controlling method, as shown in FIG. 6, an example will be explained, in which the injector 53 is opened at 0.02 second (20 msec) every one time, namely at 50 times per one second.

As shown in FIG. 4, relating to one time injecting amount of the fuel from the injector 53, when a fuel pressuring amount forms a parameter, it is presented as characteristics 44, 45, 46 and it has a proportional relationship with the opening time of the respective valves of the injectors.

In this example, when it has a value at a point 47 shown in FIG. 4, an amount being injected at one time is 0.01 cc and then with fuel injecting pulses at 50 times per one second it obtains a total fuel supplying amount of 0.5 cc per one second.

This fuel control system is a system in which the opening time of the valve of the injector is varied controlled. This injecting control is so called, as PWM control (Pulse Width Modulation control) and a pulse width is controlled freely, as a result the injecting amount per unit time is controlled surely with a good responsibility.

In addition to the above, as the controlling method of the fuel, it can realize a system for controlling the pulse interval (so called, PPM system) is realized, in which the opening time of the valve of the injector is made constant, and a system (PAM system) for variably controlling an opening degree of the valve of the injector is realized.

Third Embodiment

Hereinafter, a third embodiment of a hydrogen generating apparatus according to the present invention will be explained. This third embodiment according to the present invention, a whole fuel flow passages of the hydrogen generating apparatus according the first embodiment of the present invention is cleaning controlled, in addition to the cleaning effect of the contacting area according to the above stated centrifugal separation, it has a cycle for cleaning compulsory the spent fuel flow passage.

In this third embodiment according to the present invention, the constituting elements similarly to the first embodiment are added the same reference numerals, and the explanations will be omitted.

FIG. 7 is a perspective view showing the hydrogen generating apparatus according to the third embodiment according to the present invention, and FIG. 8 is a time chart showing operating conditions of the respective valves shown in FIG. 7.

As shown in FIG. 7, the hydrogen generating apparatus 1″ of this third embodiment according to the present invention, in addition to the constituting elements similarly to the first embodiment according to the present invention, comprises a cleaning liquid injecting means 7, a control means 8, and a rotation controlling means 9.

The cleaning liquid injecting means 7 cleans the catalyst M by blowing a cleaning liquid against the catalyst M, the control means 8 controls mainly a changeover of a supply of the fuel and the cleaning liquid, and the rotation controlling means 9 controls a rotational number of the motor 4.

The cleaning liquid injecting means 7 comprises a cleaning liquid tank 71 for storing the cleaning liquid, a piping 72 for connecting the cleaning liquid tank 71 and the pressurizing pump 52, and a valve 73 provided on the piping 72. The cleaning liquid in the cleaning liquid tank 71 is injected toward the catalyst M using the pressuring pump 52 and the injectors 53, 53.

In other words, the cleaning liquid injecting means 7 and the fuel injecting means 5 are constituted as one body by owning jointly the pressuring pump 52 and the injectors 53, 53. As the cleaning liquid, water etc., for example, is utilized.

The controlling means 8 controls the respective valves 56, 73 and electromagnetic valves. Namely, the controlling means 8 controls a valve 56 at a side of the fuel tank 51 and the valve 73 of a side of the cleaning liquid tank 71 and blows the cleaning liquid in replace of the fuel against the catalyst M.

In concretely, this controlling means 8 controls the respective valves 56 and 57 and the electromagnetic valve to blow the cleaning liquid at a predetermined shot time by closing the valve 56 and by opening the valve 73.

The rotation controlling means 9 controls the motor 4 to make higher the rotational number of the rotating disk 3 when the fuel is blown against the catalyst M than the rotational number of the rotating disk 3 when the cleaning liquid is blown against the catalyst M.

In other words, the rotational number of the motor 4 is controlled to improve a cleaning effect, such that, during the cleaning liquid is blown against the catalyst M, since a lateral acceleration G on the rotating disk 3 is proportional to a square of the rotational number, the rotational number of the rotating disk 3 is arisen and the lateral acceleration G is arisen.

Next, a cleaning method of the catalyst M using the above stated cleaning liquid injecting means 7 will be explained referring to FIG. 7 and FIG. 8.

As shown in FIG. 8, when the fuel battery is made to stop after a lapse with a predetermined time T1 (for example, 10 minutes) the valve 56 is closed according to the controlling means 8 and the valve 56 is opened with a predetermined time T2 (for example, 1-5 seconds). During this predetermined time T2, the motor 4 rotates the higher rotation number V2 than the rotation number V1 according to the rotation controlling means 9.

Accordingly, the cleaning liquid in the cleaning liquid tank 71 is blown against the catalyst M according to the pressuring pump 52 and the injectors 53, 53, and the cleaning liquid, which has reached to the catalyst M, is received a strong centrifugal force according to the rotating disk 3 which rotates under a high speed and acts to flush out surely the residual reactive compound RC.

For example, when one time cleaning is carried out every 10 minutes and the supplying amount of the cleaning liquid at the one time is 10 cc, since 60 cc cleaning liquid is supplied to the catalyst M during one hour, then the catalyst and the whole fuel flow passages are cleaned effectively.

During the above stated time, the hydrogen supply is made to stop and an electric generating operation of the fuel battery is made to stop, however the electric power supply to the controlling means 8 and the pressurizing pump 52 etc. is performed according to a battery, except for the fuel battery such as a secondary battery etc., which is connected to a normal fuel battery.

According to the third embodiment of the present invention, the cleaning condition of the whole fuel flow passage can be maintained and the stable hydrogen evaporation is realized.

As stated in above, the present invention is not limited to the third embodiment but is performed on the various embodiments. In this third embodiment, during the operation of the fuel battery system the cleaning is performed every one time every the predetermined time each, however the present invention is not limited to the above embodiment.

For example, during the stopping time of the fuel battery system, it can constitute with one time cleaning. In this case, the controlling means 8, the rotation controlling means 9 and the pressurizing pump 52 etc. may be operated according to a stopping signal from an outside portion similarly to the third embodiment according to the present invention. Further, when the fuel battery system is stopped during a long period, the system may constitute to carry out a periodical automatic cleaning.

In this third embodiment according to the present invention, the cleaning is performed only the cleaning liquid in the cleaning liquid tank 71. However, the present invention is not limited to this third embodiment, for example, when the cleaning liquid is water, the water generated at a positive pole side of the fuel battery may be reused for the cleaning use.

In this case, a water discharging port for discharging the water of the fuel battery and a water supplying port of the cleaning liquid tank 71 can be connected using a piping. In the above stated structure, a reverse valve for preventing a reversal flow and a pump for sending the water to a side of the cleaning liquid tank 71 are provided suitably.

Fourth Embodiment

Hereinafter, a fourth embodiment of a hydrogen generating apparatus according to the present invention will be explained. A fuel tank construction installed to the hydrogen generating apparatus will be explained referring to a cross-sectional view of a fuel tank shown in FIG. 9.

In FIG. 9, a fuel tank chamber 81 at a fore of use and a spent use fuel tank chamber 82 at an aft of use are separated according to a partitioning wall 83 and these fuel tank chambers 81 and 82 are enabler to accommodate totally the fore and aft use fuel with the minimum capacity in a volume of an integrated tank 80.

The borohydride fuel is, as shown in the above stated reaction formula, NaBH₄ solution at the fore use fuel and at the aft use NaBH₄ with one molecular changes to NaBO₂ by 1 to 1 and the solution of the spent use fuel is discharged.

After the pouring of the fuel, the volume of the sum of the volume of the fore use fuel and the volume of the aft use fuel is constant substantially at always. The fore use tank chamber 81 for storing the fore use fuel and the spent use tank chamber 82 are separated by the portioning wall 83 and an upper wall 86 of the fore use tank chamber 81 and the lower wall 87 of the spent use tank chamber 82 are provided.

Further, the upper wall 86 and the portioning wall 83 are combined with an expandable side wall 84, and also the lower wall 87 and the portioning wall 87 are combined with an expandable side wall 85. Then the integrated tank 80 is constituted having two chambers 81 and 82 and the fore use tank chamber 81 and the spent use tank chamber 82 are used at always under a filling-up condition, the tank volume between the upper wall 86 and the lower wall 87 becomes to have the substantial same volume as stated in above. Accordingly, the integrated tank 80 is formed to enable accommodate the minimum capacity in the volume of the integrated tank 80.

The pouring of the fuel is carried out using a pouring piping 90, and the fuel supply is carried out to connect to the valve 56 shown in FIG. 1 via a fuel supplying piping 88 by passing through a bendable piping 94 against the upper and lower move of the partitioning wall 83.

Further, the spent use fuel is pored into the spent use fuel tank chamber 82 through a recovery fuel pouring piping 89 by passing through a pouring pump 92 from the deriving tube 21 f shown in FIG. 1. The spent use fuel stored in the spent use fuel tank chamber 82 is discharged from a discharging piping 91 and is recovered at the outer portion.

Since the borohydride fuel is a noninflammable alkali fuel, which can operate under the normal temperature and the normal pressure environment, and since the tank constituting material is a resin system material or a stainless material, accordingly the expandable side walls 84 and 85 are constituted stably.

According to the present invention, since the reactive compound generated together with the hydrogen gas generation is centrifugally separated according to the rotating body, the reactive compound can be prevented from adhering to the catalyst. 

1. In a hydrogen generating apparatus in which in a rector for accommodating a catalyst, said catalyst and a borohydride fuel are reacted and hydrogen is generated, wherein the hydrogen generating apparatus comprises: a fuel tank for storing said borohydride fuel; a rotating body to which said catalyst is fixed; a rotation driving means for rotating said rotating body; and a fuel injecting means for blowing said borohydride fuel against said catalyst which is subjected under a rotation state.
 2. A hydrogen generating apparatus according to claim 1, wherein the hydrogen generating apparatus comprises further a controlling means for said fuel injecting means; and said controlling means controls to supply intermittingly said borohydride fuel with a predetermined time interval against said catalyst.
 3. A hydrogen generating apparatus according to claim 1 or claim 2, wherein the hydrogen generating apparatus comprises further a cleaning liquid injecting means; and said cleaning injecting means blows out a cleaning liquid against said catalyst.
 4. A hydrogen generating apparatus according to claim 3, wherein said fuel injecting means includes said fuel tank for storing said borohydride fuel; said cleaning liquid injecting means has a cleaning liquid tank for storing said cleaning liquid; said fuel injecting means and said cleaning liquid injecting means are constituted as one body by own joining an injector for blowing out said borohydride fuel or said cleaning liquid against said catalyst and a pressurizing pump for pressurizing said cleaning liquid sent from said cleaning liquid tank to said injector.
 5. A hydrogen generating apparatus according to claim 3 or claim 4, wherein the hydrogen generating apparatus comprises further a rotation controlling means; said rotation controlling means controls said rotation driving means to arise a rotational number of said rotating body during a blowing-out time of said cleaning liquid against said catalyst.
 6. A hydrogen generating apparatus according to claim 1, wherein the hydrogen generating apparatus comprises further an integrated tank for storing a fore use fuel and for storing a spent use fuel; said tank comprises a tank chamber for storing said fore use fuel and a tank chamber for storing said spent use fuel; said fore use tank chamber and said spent use tank chamber are combined as one body of said integrated tank by separating with a portioning wall; a side of said fore use tank chamber and a side wall of said spent use tank chamber are constituted with an expandable structure, respectively; and said fore use tank chamber and said spent use tank chamber are used under a condition where both of said fore use tank chamber and said spent use tank chamber are filled up at always; thereby an occupied volume of said integrated tank being as one body is used with the minimum volume. 